pharmacology: diuretics

Question 1

what are the categories of diuretics?

Answer 1

osmotic diuretics, carbonic anhydrase inhibitors, loop diuretics, thiazides, K+ sparing agents

Question 2

what are the osmotic diuretics?

Answer 2

mannitol (IV) - inhibits water reabsorption throughout the tubule which increases urine volume

Question 3

mannitol uses and side effects

Answer 3

uses: decreases IOP in glaucoma
decreases intracerebral pressure
oliguric states (rhabdo)

SE: acute hypovolemia

Question 4

what are the carbonic anhydrase inhibitors? mechanism?

Answer 4

acetazolamide and dorzolamide
mechanism: carbonic anhydrase inhibition resulting in: 
decreased H formation inside PCT cell
decreased Na/H antiport
increased NA and HCO3 in lumen
increased diuresis

Question 5

carbonic anhydrase inhibitors uses

Answer 5

glaucome, acute mountain sickness, metabolic alkalosis (loss of bicarb)

Question 6

carbonic anhydrase inhibitors side effects

Answer 6

bicarbonaturia and acidosis with hypokalemia******
hyperchloremia
paresthesias
renal stones
sulfonamide hypersensitivity

Question 7

what are the loop diuretics? mechanism?

Answer 7

ethacrynic acid and furosemide
mechanism: Na/K/2Cl transporter inhibition resulting in:
decreased intracullular K in TAL
decreased back diffusion of K
decreased positive potential
decreased reabsorption of Ca and Mg
increased diuresis

Question 8

ethacrynic acid and furosemide uses

Answer 8

acute pulmonary edema, heart failure, hypertension, refractory edemas, acute renal failure, anion overdose, hypercalcemic states

Question 9

ethacrynic acid and furosemide side effects

Answer 9

sulfonamide hypersensitivity (furosemide)
hypokalemia and alkalosis
hypocalcemia
hypomagnesemia
hyperuricemia
ototoxicity

Question 10

ethacrynic acid and furosemide drug interactions

Answer 10

aminoglycosides (enhanced ototoxicity)
lithium (chronic loop administration, decreased clearance)
digoxin (increased toxicity due to electrolyte disturbances)

Question 11

what are the thiazides? mechanism?

Answer 11

hydrochlorothiazide and indapamide
mechanism: Na/Cl transporter inhibition resulting in:
increased luminal Na and Cl in DCT
increased diuresis

Question 12

thiazides (hydrochlorothiazide and indapamide) uses

Answer 12

HTN, CHF
nephrolithiasis (calcium stones)
nephrogenic diabetes insipidus

Question 13

thiazides (hydrocholorthiazide and indapamide side effects

Answer 13

sulfonamide hypersensitivity
hypokalemia and alkalosis
hypercalcemia
hyperuricemia
hyperglycemia
hyperlipidemia

Question 14

hydrochlorothiazide and indapamide drug interactions

Answer 14

digoxin

avoid in DM

Question 15

what are the K sparing agents

Answer 15

spironolacton, amiloride, triamterene

Question 16

spironolactone mechanism and uses

Answer 16

mechanism: aldosterone-receptor antagonist
uses: hyperaldosteronic state
adjunct to K wasting diuretics
antiandrogenic uses (female hirsutism)
CHF

Question 17

spironolactone side effects

Answer 17

hyperkalemia and acidosis

antiandrogen (eplerenone selective)

Question 18

amiloride and triamterene mechanism, use, side effects

Answer 18

mechanism: Na channel blockers
use: adjunct to K wasting diuretics, lithium induced nephrogenic diabetes insipidus
side effects: hyperkalemia and acidosis

Question 19

which diuretics cause blood acidosis?

Answer 19

acetazolamide (secretion of HCO3), amiloride, tramterene, spironolactone, eplerenone

Question 20

which diuretics cause blood alkalosis

Answer 20

ethacrynic acid, furosemide, hydrochlorothiazide, indapamide